Hydrocarbon oils having improved water tolerance



United States Patent 3,265,474 HYDROCARBON OILS HAVING IMPRQVED WATER TOLERANCE Joel R. Siege], Elizabeth, NJ, assignor to Esso Research and Engineering Company, a corporation of Delaware No Drawing. Filed Oct. 6, 1961, Ser. No. 143,287 The portion of the term of the patent subsequent to Nov. 13, 1978, has been disclaimed 4 Claims. (Cl. 44-62) This application is a continuation-in-part of Serial No. 770,520, filed October 29, 1958, now US. Patent No. 3,008,813.

The present invention relates to improvements in the water tolerance of organic liquids, and more particularly relates to surfactants containing petroleum fuels and hydrocarbon oil products having incorporated therein additive agents singularly adapted to inhibit and reduce the formation of persistent haze and stable emulsions when such products are contacted with water during handling and storage.

Various additives possessing surfactant properties are being employed with increasing frequency in water immiscible, organic liquids such as dry cleaning fluids, solvents and fuels to function as dispersants, oxidation and rust inhibitors, anti-icing agents, pour point depressants, detergents, etc. In particular, ashless, oil soluble, polymeric dispersants have largely displaced metal sulfonates, metal naphthenates and similar compounds for use as stabilizing additives in petroleum distillate fuels and related hydrocarbon oil products because of their increased ability to suspend insoluble degradation products formed in such oils. Sludge and sediment which might otherwise tend to clog fuel lines, orifices, screens and tilters through which the oils must pass are held in suspension to a much greater extent by the polymeric additives than by the additive materials formely employed. These increased dispersive properties, although highly desirable from the standpoint of oil stability, have given rise to water tolerance problems much more serious than those heretofore encountered. Polymeric surfactants employed as additives exhibit particularly pronounced tendencies to suspend any water with which the organic liquid mediums come into contact, and hence extremely persistent haze and stable emulsions are formed upon contact of oils containing the polymeric additives with water. Since an aqueous phase exists in most tanks and other vessels containing such oils, liquids such as hydrocarbon and petroleum fuels, haze formation and emulsification are almost impossible to avoid. As a consequence, the marketability of these organic liquids such as dry cleaning solvents and particularly of distillate fuels, lubricating oils, transformer oils, turbine oils, jet fuels, gasoline, heating oil, and other petroleum products in which surfactant additives are used is often seriously affected.

The present invention provides a class of new and improved additives which are surprisingly effective for increasing the Water tolerance of water immiscible organic liquids such as petroleum distillate fuels and similar liquid hydrocarbon oi-ls containing polymeric additives. In accordance with the invention, it has now been discovered that the addition of minor amounts of certain quaternary ammonium compounds to such liquids greatly reduces the persistence of haze and emulsions formed when the products are contacted with water, and thus permits their trans- "ice portation and storage in the presence of an aqueous phase without adverse results.

The quaternary ammonium compounds which have been found to be singularly effective for improving the Water tolerance of petroleum products in accordance with the invention are dialkyl dimethyl quaternary ammonium salts having alkyl groups which each contain from about 12 to 14 carbon atoms. It has been found that compounds of this type are critical for purposes of the invention. Closely related tetraalkyl ammonium salts such as the trialkyl monomethyl ammonium chlorides and the monoalkyl trimethyl ammonium chlorides are not effective for reducing haze and emulsion formation, are readily extracted by water, adversely affect the action of the polymeric stabilizing additives, or are otherwise unsuitable for purposes of the invention. Specific examples of dialkyl dimethyl ammonium salts which may be employed are diododecyl dimethyl ammonium chloride, ditridecyl dimethyl ammonium chloride, dodecyl tridecyl dimethyl ammonium chloride, dodecyl tetradecyl dimethyl ammonium chloride and tridecyl .tetradecyl dimethyl ammonium chloride. The nature of the anionic radical is not critical and may be a halide such as a chloride, iodide or bromide, an alkoxy radical such as methoxy, ethoxy, a weak acid radical like acetate, or a strong acid radical like sulfate, nit-rate, or a hydroxide or any combination thereof. Due to commercial availability, the halides, particularly the chloride, are the prefererd anionic radical. Also useful for purposes of the invention are dialkyl dimethyl ammonium chlorides derived from naturally occurring materials such as coconut oil which contain at least 50% by Weight of C to C alkyl groups. For example, dicocodimethyl ammonium chloride, derived from coconut oil, contains from about 55 to about of C to C alkyl groups, and has been found eminently satisfactory for purposes of the invention. The

alkyl groups outside the C to C range in these mixed dialkyl dimethyl ammonium chlorides apparently do not contribute to the improved water tolerance of the products. Such mixed dialkyl dimethyl ammonium halides are generally referred to as technical dilauryl dimethyl ammonium chlorides and are preferred for the purposes of the invention.

Additives which tend to promote stable aqueous emulsions, haze and poor water shedding and tolerance properties in water immiscible organic liquids are those surfactant type additives and particularly those oil soluble, ashless, polymeric, dispersant additives which contain one, two, three or a plurality of active polar groups or functions such that the molecule includes both polar hydrophilic and nonpolar lipophilic groups or combinations thereof. Generally, the number, type and frequency of these radicals are such as to give the molecule a dipole moment, and are balanced to obtain the desired degree of surfactant characteristics. The oil soluble surface active agents are those additives which reduce the interfacial tension between the organic liquid and the water contacted so as to suspend small droplets of the water as a water-in-oil emulsion in the organic liquid. The surface a-ctive agents responsible for these conditions may be anionic, cationic or nonionic type additives. For example, vhydrocarbon polymers such as polyolefins like polybutene or alkylated polystyrene possess few surfactant characteristics or properties, while similar phosphosulfurized products due to the polar group therein are active surfactants which promote water haze. Nonlimiting examples of polar groups whose presence in oil soluble, polymeric additives creates surfactant properties and thus promotes haze problems include sulfonic and t-hiophosphoric acid groups, ethylenically unsaturated acid or ester radicals like maleic anhydride and vinyl acetate radicals which contain carbonyl radicals, oxygen, etc. The additives employed in hydrocarbon and :fuel products which generally function as dispersants in middle distillate products or as pour depressants in residual -fuel products or as detergent agents in gasolines are particularly prone to create haze problems due to the nature of the molecules employed. These additives in general are polymers and copolymers of unsaturated organic esters, nitriles and similar monomers containing vinyl, vinylene or vinylidene linkages. The dialkyl dimethyl ammonium chlorides employed in accordance with the invention have been found effective when used in products containing a wide variety of such polymeric dispersants.

TYPES OF HAZE PROMOTING SURFACTANTS 1. One class of oil soluble, polymeric, dispersant additives in conjunction with which the dialkyl dimethyl am monium chlorides have been found to be particularly effective are those polymers which are prepared by the copolymerizat-ion of an aliphatic haloepoxy mixed ester of an unsaturated conjugated dibasic acid with a polymerizable organic monomer containing one or more ethylenically unsaturated link-ages and particularly those C to C alkyl hal-oalkenyloxy mixed esters of butenedioic acids with polymerizable organic monomers containing a vinyl group, particularly a terminal vinyl group attached through an oxygen, nitrogen, sulfur, or carbon atom to a saturated aromatic or aliphatic radical. The alkyl chloropropyleneoxy mixed esters used as one of the components of such copolymers are prepared by first reacting a C to C unsaturated conjugated dibasic acid such as maleic acid, fumaric acid, citraconic acid, mesaconic acid or a mixture of such acids or their anhydrides or acid halides, when they exist, with a long chain saturated aliphatic alcohol to produce a half ester. Suitable alcohols for this purpose are those containing from about 8 to about 24 carbon atoms per molecule, preferably about 8 to 18 carbon atoms per molecule. Straight chain primary alcohols such as dodecyl, cetyl, eicosyl and docosyl alcohols are preferred but branched chain alcohols such as 2-ethylhexanol-l and C oxo-alcohols, secondary alcohols such as capryl alcohol and mixtures of straight and branched chain alcohols may also be used. Commercially marketed mixtures of alcohols of the requisite chain length, such as those obtained by the hydrogenation of coconut oil may also be used.

The half ester produced in the above manner is then reacted with a halosubstituted C to C alkylene epoxide such as epichlorohydrin, epibromohydrin, chlorobutylene epoxide, but preferably with epichlorohydrin in the pres ence of either an acidic or a basic catalyst such as boron fluoride or sodium hydroxide to produce the mixed ester. The ratio of the half ester to epichlo-rohydrin in the reaction mixture may range from about 1:1 to 1:4. Addition of the epichlorohydrin takes place through the epoxy group and the chlorine atom is unaffected. The mixed ester may thus contain from 1 to about 3 or more chlorine atoms. This mixed ester may contain some free bons such as vinyl aromatics like styrene, aliphatics like isobutylene, isoprene and butadiene, esters such as vinyl propionate and methyl methacrylate, ethers such as divinyl ether, and nitriles such as acrylonitrile and vinylaceton-itrile, halides like vinylene chloride or vinylidene chloride, etc. Mixtures of such monomers containing vinyl groups with other copolymerizable materials, long chain alcohol esters of unsaturated conjugated dibasic acids such as lauryl maleate and tallow f-umarate for example, may also be used. Vinyl esters of short chain fatty acids, particularly vinyl acetate and mixtures of such esters with turnarate or maleate esters of long chain aliphatic alcohols containing from about 8 to about 20 carbon atoms per molecule are preferred monomers for preparation of the copolymers with the mixed esters. The resulting copolymers are oil soluble and preferably have molecular weights between about 6,000 and about 20,000 Staudinger. Such copolymers are described in copending application Serial No. 673,156, filed July 22, 1957.

II. A second class of polymeric dispersant additives with which the dialkyl dimethyl ammonium chlorides are especiaily effective are oil-soluble, nitrogen-containing addition type copolymers prepared by copolymcrizing an amine-free monomer containing one piolymerizable ethylenic linkage and an aliphatic hydrocarbon chain of from 8 to 18 carbon atoms with a monomer containing a nitrogen atom and one polymerizable ethylenic linkage. Such copolymers may be prepared, for example, by the copolymerization of an acrylic or alpha-substituted acrylic ester of an aliphatic alcohol containing an average of from 8 .to- 18 carbon atoms, such as lauryl methacrylate,

with an ethylenically unsaturated compound containing a basic amino group, such as beta dimethyl aminoethyl methacrylate. Other specific examples of the amine-free monomers containing a polymerizable ethylenic linkage and a C to C aliphatic chain include the tridecyl, cetyl and octadecyil esters of acrylic and methacrylic acids. Also suitable are esters of these acids prepared from mixtures of alcohols such as those containing primary alcohols of from 10 to 18 carbon atoms derived by the hydrogenation of coconut oil and sold under the trade name Lorol. A typical mixture consists chiefly of lauryl alcohol having 12 carbon atoms per molecule and has the following approximate composition.

Alcohol constituent: Weight percent The polymerizable ethylenically unsaturated compounds containing a nitrogen-containing group which are used in forming the second class of preferred copolymers suitable for use in accordance with the invention include the basic tertiary amino-alkyd acry-lates, such as the dialkyl amino-alkyl acrylates and alpha hydrocarbon-substituted acryl-ates, beta dimethyl aminoethyl acrylate and methacrylate, and their h omollogs, isomers, and analogs. The nitrogen may be a member of a heterozcycle where the polymenizable ethytlenic unsaturation is extra-nuclearly bonded to the hetero-cycle, such as the vinyl pyridines and vinyl pyrrolidone.

Limited amounts of other wpolymerizable monomers in addition to those described above may be incorporated into the copolymers of the second preferred class as filler materials. Such filler materials include vinyl and allyl torma-tes, acetates, propionates, isobutylene, styrene, methyl methacrylate, ethyl vinyl ether and the like. The final cop-olymer may contain from about 20% to about 99% of the nitrogen-free monomers, from about 0.5% to 50% of the nitrogen-containing monomer, and from about 0 to about 79% of the monomer used as a filler material.

'ene pentaamine to form the imide.

Many of the polymeric additives falling Within the second class are described in detail in US. Patent 2,737,452, issued March 6, 1956, hereby incorporated by reference in its entirety.

III. Another class of haze inducing, ashless polymers includes those copolymers of a vinyl substituted, heterocyclic, nitrogen base compound such as vinyl pyridines and vinyl pyrrolidones and their lower alkyl substituents with the aliphatic esters of acrylic and C to C alkyl acrylic acids, for example, a oopolymer of from about 1 to 30% by weight of a N-vinyl pyrrolidone or C to C alkyl substituted, N-vinyl pyrrolidone and from 70 to 99% by weight of a C to C alkyl ester of acrylic and methacrylic acids or C to C alkyl substituted acrylic acid. These copolymers are more fully described in British Patents 760,554 and 808,665, hereby incorporated by reference in their entirety, and are generally employed as detergent and antiwear additives in lubricating oils, gasolines, and diesel fuels.

IV. A further class of polymers which promotes stable water emulsions includes those lubricating oil V.I. improver, additive, oil soluble tenpolymers prepared by the copolymerization of from 1 to 6 Weight percent of maleic anhydride, 40 to 80 Weight percent of a vinyl ester of a short chain fatty acid such as vinyl acetate and 20 to 50 weight percent of a C to C aliphatic ester of a butenedioic acid like an alkyl fumarate such as lauryl furnarate having an average degree of polymerization between 500 and 10,000, which are more fully described in US. application 769,991, filed October 28, 1958.

V. Another class of polymeric agents which tends to create poor water tolerance properties are those copolymers employed in middle distillate fuels subject to low temperatures as pour point depressants, and include those polymers prepared by the copolyrnerization of ethylene with from 1 to about 40% by weight, e. g. 15 to 25%, of vinyl ester of C to C fatty acid such as a short chain fatty acid like vinyl acetate and having a molecular Weight between 1000 and 3 000, more fully described in US. application 831,244, filed March 5, 1958.

VI. A well known class of detergent polymers generally employed in lubricating oils and gasolines and which promotes poor water shedding properties includes those phosp-hosulfu-rized polyolefins and bright stock residuurns prepared by the reaction of from 1.0 to about 50.0, e.g. 5 to 25% by weight of a phosphos-ul-furizing agent like P 8 with a (1 polym-onoolefin such as a monoolefin like polyisobutylene having a molecular weight of from 500 to about 20,000. These acidic phosphosulfur-ized products may be employed alone or hydrolyzed by steam stripping the product at a temperature between 100 and 200 C. to remove volatile lay-products and to reduce the acid number to about 25, or treated or neutralized with a basic agent such as with amines, ammonia, quaternary ammonium salts, alkali or alkaline earth carbonates, hydroxides, C to C alkylene oxides like ethylene oxide, urea, guanidine, and the like, or any combination thereof. These products are more fully described in British Patents 838,928, 792,553, and 792,593, Which are hereby incorporated by reference in their entirety.

VII. A further class of polymeric agents which degrade the water tolerance properties of petroleum products in which they are incorporated includes C to C e.g. C to C alkenyl succinic acid anhydrides and their neutralized products and derivatives such as those products prepared by treating the monalkenyl succinic acid or acid anhydride with amines, ammonia, quaternary ammonium salts, alkylene oxides like ethylene oxide, alkali and alkaline earth oxides and the like, and particularly the C to C alkenyl succinic imides prepared by reacting a monoalkenyl succinic acid anhydride wherein the alkenyl radical is a C to C polyolefin like polybutene and has an average molecular weight of from 600 to 10,000 with a polyamine like an alkylene diamine such as tetraethyl- Polymers of this type are described in part in French Patent 1,254,094 and Australian Patent 63,806/ 60, hereby incorporated by reference in their entirety.

Many other polymeric surface active additives suitable for the stabilization of hydrocarbon oils will be familiar to those skilled in the art. The stabilization of haze and emulsions is a universal property of such additives, and the dialkyl dimethyl ammonium chlorides may be employed with a wide variety of such materials. Representative examples of other ashless, oil soluble polymeric stabilizing additives are described in U.S. Patent 2,737,- 496, in US. 2,800,452, and in US. 2,958,590.

The foregoing polymeric additives may be employed alone or in combination in organic liquids for a variety of primary purposes, but the ashless, polymeric dispersant additives in fuel oils are sometimes employed in combination with amine inhibitors and metal deactivators and, in particular, tertiary alkyl primary amines and N,N'- disalicylidine-diamino alkane. Such amines effect a considerable improvement in the stabilizing action of the polymeric dispersants. These amines do not, however, overcome the tendency of such dispersants to suspend Water in oils in which they are present, and hence do not prevent the Water tolerance problem caused by the dispersants. The dialkyl dimethyl ammonium chlorides may therefore be employed to advantage in oils containing both a polymeric dispersant and a tertiary alkyl primary amine,

The tertiary alkyl primary amines useful with the polymeric dispersants described above in general are those having two alkyl groups of from 1 to 3 carbon atoms attached to the tertiary carbon atom. Tertiary alkyl primary amines containing a total of from 8 to 18 carbon atoms per molecule are preferred. Particularly preferred are C tertiary alkyl primary amines. Mixtures of such amines such as those derived from polyolefins may also be used and are more fully described in U.S. 2,945,749, herein incorporated by reference in its entirety.

Tertiary alkyl primary amines such as those described above are employed in combination with the polymeric dispersants in concentrations such that the ratio of amine to dispersant in the oil ranges from about 0.5/1 to 25/ 1, for example, 1/1 to 18/1, or 2 to 1, to about 9 to 1. Amine concentrations between about 0.003 wt. percent to about 0.8 Wt. percent are especially effective.

Ashless polymeric dispersants in combination with amine metal deactivators are frequently employed in aviation turbine fuels to promote enhanced thermal stability at high temperatures. One class of metal deactivators is N,N-disalicylidene-diamino alkanes wherein the alkane can be ethane, propane, butane or pentane, and the amino groups are on carbon atoms separated by no more than one carbon atom. A particularly desirable member of this class is N,N'-disalicylidene-1,2-propane-diamine employed at a concentration level of from 0.001 to about 0.81 wt. percent.

VIII. Further oil soluble, surface active agent, haze promoting additives include the metal, for example, the alkali and alkaline earth salts and ammonium salts of phenol sulfidessuch as barium phenol sulfide; alkyl phenol sulfide like calcium dodecyl phenol sulfide; petroleum sulfonic and naphthenic acids having an average molecular Weight of to 1200 such as ammonium sulfonate, barium naphthenate, lecithin; fatty acid soaps like alkali and alkaline earth and ammonium oleates, stearates, the alkali salts of high molecular weight alkyl sulfates and sulfonates and the like.

The organic liquid in which surface active agents may be employed include those Water immiscible organic liquids such as dry cleaning solvents like halogenated hydrocarbons, carbon tetrachloride, carbon disulfide, perchlorocthylene, tetrafluoroethylene, bromobenzene; aromatic alicyclic and aliphatic solvents like xylene, benzene, toluene, cyclohexanone, and the like.

The oils in which the additives of the invention may be incorporated are liquid petroleum distillate products boiling in the range between about 75 F. and about 900 F. e.g. 75 F. to 750 F. Such products include gasolines, aviation turbojet fuels, kerosenes, diesel fuels, transformer oils, turbine oils, heating oil, and lubricating oils. The additives are particularly effective in distillate fuels boiling in therange between about 250 F. and about 750 F. Such fuels include turbojet engine fuels, diesel fuels and heating oils which have particularly poor stability properties and require the use of relatively large amounts of the polymeric dispersant additives. Aviation turbojet engine fuels are defined by US. Miliary Specifications MIL-F-5624C, MIL-F-25524A, and MIL-F- 25558A and are generally referred to as JP-4, JP-S and JP-6. Diesel fuels in connection with which the additives of the invention are particularly useful are more fully described in ASTM Specification D97553T and may be used in stationary, marine and automotive type engines. Typical of the heating oils in which the additives may be employed are those described in ASTM Specification D 39648T, particularly those in Grades 1 and 2 thereof.

The polymeric additives and particularly the dispersants are generally employed in petroleum hydrocarbon products such as those described above in concentrations ranging from about 0.001% and about 1% by weight. Concentrations of from 0.001% to .05% are generally preferred. The dialkyl dimethyl ammonium chlorides which are used in such oils may be incorporated therein in concentrations in the range of from about 0.00025 wt. percent to about 0.01 wt. percent. Chloride cencentrations in the range of from about 0.0005 wt. percent to about 0.001 wt. percent have been found to be generally effective and are preferred, since it has been found that the stabilizing properties of some dispersant additives may suffer when the dialkyl dimethyl ammonium chlorides are present in very high concentrations.

The quaternary ammonium compound may be incorporated int-o the fuels by dissolving it in a suitable solvent such as isopropanol, butanol, benzene or the like and then adding the resultant solution to the oil in quantities sufficient to give the desired additive concentrations. If desired, additive concentrates containing both the polymeric dispersant stabilizing additive, a tertiary alkyl amine and the dialkyl dimethyl quaternary ammonium compound in a suitable solvent such as kerosene may be prepared. A typical additive concentrate would comprise:

Weight Percent Range Preferred A. Oil soluble dispersant polymer such as polymers of Class I or II or others 20-80 25 A. 01 -1 tertiary alkyl primary amine. 80-20 75 100 100 Dicoco dimethyl ammonium chloride, 1 5-25 1 1 Percent of the above total weight.

Example 1 Samples of a petroleum distillate heating oil which had been stabilized by the inclusion therein of 0.01% by weight of various, polymeric dispersant additives were tested to determine the persistence of the haze formed when the fuel was contacted with water and the stability of the emulsions formed during such contacting. The fuel employed was a blend consisting of about 50% by volume of virgin gas oil and about 50% by volume of catalytically cracked stock. Typical inspections for a fuel of this type are as follows. Gravity, API 34.6 Color, Tag-Robinson 16 /2 Pensky-Martens flash, F 185 Sulfur, wt. percent 0.32 Neutralization No. 0.02 Aniline point, F. 109.5 ASTM distillation:

Initial boiling point, F. 324 10% point, F 396 50% point, F 482 point, F 597 Final boiling point, F 643 Conradson carbon residue, wt. percent 0.006

The persistence of the haze formed in this oil upon contact with water was measured in Waring Blendor Haze Tests wherein five milliliters of Water and 500 milliliters of the 'oil were mixed in a Waring Blendor for a period of five minutes, the oil-water mixture was then allowed to stand for six hours, and the amount of light which. was transmitted through the oil under standardized conditions was measured. The light transmission was expressed as a percentage of the total light emitted from the source. This test has been found to be an extremely effective means for determining the degree to which haze is present in hydrocarbon oils and is recognized as reliable throughout the petroleum industry.

Herschel Emulsion Tests were carried out to determine the effect of the additives upon emulsification by stirring 40 milliliters of oil and 40 milliliters of water for five minutes at a temperature of 77 F. to form an emulsion, letting the mixture stand for 15 minutes, and then measuring the volume of the emulsion phase. Similar tests are widely used for determining the emulsification tendencies of turbine oils in accordance with ASTM Standard D-140156T and in similar applications.

Three different tetraalkyl ammonium chlorides were added in concentrations of 0.0008 wt. percent to separate samples of the same heating oil containing 0.01 wt. percent of the same polymeric dispersant additive. The tetraalkyl ammonium chlorides employed were as follows:

(1) Dicoco dimethyl ammonium chl0ride.-A dialkyl dimethyl ammonium chloride having mixed alkyl groups derived from coconut oil as follows: 8% C radicals, 7% C radicals, 48% C radicals, 18.5% C radicals, 8% C radicals and 10.5% C radicals.

(2) Disoya dimethyl ammonium chloride.A dialkyl dimethyl ammonium chloride having mixed alkyl groups derived from soybean oil which include about 8% C rarllicals, about 88% C radicals and about 4% C (nadica s.

(3) Dihydrogenated tallow dimethyl ammonium chloride.-A dialkyl dimethyl ammonium chloride having mixed C and C alkyl groups derived from hydrogenated tallow.

('4) Tallow trimethyl ammonium chl0ride.A monoalkyl trimethyl ammonium chloride having mixed C and C alkyl groups derived from tallow.

The oil samples containing the polymeric dispersant additive and the above tetraalkyl ammonium chlorides were then subjected to Waring Blendor Haze Tests and Herschel Emulsion Tests, both with and without prior water extraction. About 1% water was used in the water g. extraction step. The results obtained in these tests are in Table I.

to The data obtained with tallow trimethyl ammonium chloride demonstrate that a satisfactory additive must not TABLE I.EFFECT OF TETRAALKYL AMMONIUM CHLORIDES UPON HAZE AND EMUL- SIFICATION IN HEATING OILS Waring Blendor Haze Test, Herschel Emulsion Test,

Percent Light Transmis- Milliliters Emulsion After sion After 6 Hours Minutes Fuel Fuel Not Fuel Ex- Fuel Not Fuel Ex- Water tracted Water tracted Extracted With Water Extracted With Water Base Heating Oil 94 0 0 Base Heating Oil+0.01% Additive A 1 14 12 4 31 Base Heating Oil+0.01% Additive A+0.0008% D1- coco Dimethyl Ammonium Chloride 95 81 1 2 Base Heating Oil+0.01% Additive A+0.0008% Disoya Dimethyl Ammonium Chloride 54 3 18 Base Heating Oil+0.01% Additive A+0.0008% Dihydrogenated Tallow Dimethyl Ammonium Chloride 53 12 18 15 Base Heating Oil+0.01% Additive A+0.0008% Tallow Trimethyl Ammonium Chloride 90 (i Base Heating Oil+0.01% Additive B 48 64 Base Heating Oil+0.01% Additive B+0.00

coco Dimethyl Ammonium Ch1oride 92 88 Base Heating Oil+0.01% Additive B+ Disoya Dimethyl Ammonium Chloride" 36 60 Base Heating Oil+0.01% Additive B+0.0008% Dihydrogenated Tallow Dimethyl Ammonium Chloride 29 27 l Additive A was a copoly-mer oil mol of vinyl acetate, 0.25 mol of isooctyl chloropropyleneoxy maleate, and 0.75 mol of mixed C1 to C 5 alkyl fumarates, wt. percent concentration in benzene.

2 Additive B was a mixture of 8 parts of a C tertiary alkyl primary amine and 1 part of a copoly-mer prepared from 8 parts of lorol methacrylate and 2 parts of beta diethyl aminoethyl methacrylate.

From the Waring Blendor Test results in the above table it can be seen that the light transmission through the base heating oil containing the polymeric dispersant additive was quite low, indicating a high haze level. The fact that this haze persisted even though six hours had elapsed between the time the water and oil were mixed and the time the light transmission values were determined shows that it was exceptionally stable due to the presence of the polymeric dispersant in the oil. The results obtained with the samples containing the dicoco dimethyl ammonium chloride demonstrate the remarkable eifectiveness of this additive for preventing the formation of per sistent haze in oils. This effectiveness is particularly outstanding in view of the fact that this material is marketed commercially for use as a general emulsion stabilizer and might therefore be expected to promote, rather than hinder, the formation of persistent haze. The disoya dimethyl ammonium chloride and the dihydrogenated tallow ammonium chloride, both of which have structures very similar to that of dicoco dimethyl ammonium chloride but do not contain predominantly C and C alkyl groups, were much less elfective. Results of the Herschel Emulsion Tests confirm these findings. The above data also demonstrate that the effectiveness of dicoco dimethyl ammonium chloride is not seriously affected by water extraction. The disoya dimethyl ammonium chloride and the dihydrogenated tallow ammonium chloride, on the other hand, were much less effective after water extraction.

be extracted by water to any significant extent. The tallow trimethyl ammonium chloride was largely removed from the fuel during the extraction step and hence aiforded little protection against the formation of persistent haze when the fuel was subsequently subjected to the Waring Blendor Test. The dicoco dimethyl ammonium chloride, on the other hand, was extracted only to a slight degree and was nearly as effective following the water extraction step as it was prior to water extraction. Since distillate fuels and other petroleum products in which polymeric dispersant additives are frequently employed are often contacted with relatively large quantities of water under conditions which may lead to the extraction of additives contained therein, this difference between the dicoco dimethyl ammonium chloride and the tallow trimethyl ammonium chloride is a significant one.

Example 2 In order to determine the eifectiveness of commercial demulsifiers for use in oils containing polymeric dispersant additives, tests similar to those described above were carried out upon samples of heating oils containing such inhibitors. The heating oils employed had properties similar to those of the oil used in the preceding example and contained polymeric dispersants in 0.01 wt. percent concentrations. The samples were first subjected to Waring Blendor Haze Tests. If the results from this test indicated that the particular inhibitor showed promise, Her-schel Emulsion Tests were carried out. The overall results obtained are summarized as follows.

TABLE II.-EFFECT OF COMMERCIAL QUATE RNARY AMMONIUM SALTS AND DEMULSIFIERS UPON HAZE IN OILS CONTAINING POLYMERIC DISPE RSANTS Waring Blendor Herschel Emulsion Inhibitor Dispersant Haze Test, Percent Test, Mllliliters Additive Light Transmitted Emulsion After 15 After 6 Hours Minutes None Nalquat 6-8-11 (0.001%) Nalquat G-8-l2 (0.001%)- Nalquat G8l3 (0.001%) Nalquat G-8-13 (0.0008%) Nalquat G-9-12 (0.001%) Nalquat (3-9-13 (0.001%) Nalquat G-9-13 (0.0008%). A.-.

None. None- None B 2 Tretolite F46 (0.01%) B--.

Tretolite F-65 (0.01%) Tretolite F-fifi (0.01%) Tretolite F-Sfi (0.01%)

Tretolite F-98 (0.01%) Tretolite F-90 (0.01%)

1 Dispersant additive A was a copolymer of 1 mol of vinyl acetate, 0.25 mol of isoootyl chloropropyleneoxy maleate, and 0.75 mol of mixed Clo-C15 alkyl fumarates, 50 wt. percent concentration in benzene.

1 Dispersant additive B was a copolymer prepared ilrom Sparts oi Lorol methacrylate and 2 parts of beta diethylaminoethyl methacrylate.

Tests were carried out on 70 other commercial demulsifiers by adding 0.005 wt. percent of the material to be tested to 250 m1. of heating oil containing 0.01 Wt. percent of polymeric dispersant B, shaking the sample with 1% water, and then usually observing rate at which the haze cleared. Sixty-three of these commercial additives were found to promote haze in the presence of the polymeric dispersant, six had no visible influence upon the hazing properties of the oil containing dispersant, and one indicated a slight improvement in haze clearing rate. When this latter additive was retested, the results could not be duplicated.

EXAMPLE 3 Tests were carried out to determine the effect of dicoco dimethyl ammonium chloride upon the stability of distillate petroleum products. The test employed was the Accelerated Storage Stability Test described in detail in New Fast Test Method for Distillate Storage Stability by W. A. Conrad, N. L. Shipley and T. S. Tutweiler on page 145 of Petroleum Processing for September 1946. Briefly, the Accelerated Filter Plugging Test consists of heating a sample of the oil to be tested at a controlled rate for 16 hours to a final temperature of 230 F. in order to accelerate the formation of sediment in the oil. The oil sample is then cooled and passed through a felt filter pad at a constant rate of 1 gallon per hour. As sediment accumulates on the filter under constant oil flow conditions, the pressure drop across the filter increases. After 12 liters, the Standard Volume used in the test, has been filtered, a record is made of final pressure drop across the filter, the weight of sediment collected is determined, and the appearance of the tfilter is noted. These criteria are individually interpreted on a demerit basis wherein is an excellent rating and is a very bad rating. The values for the 3 criteria, \final pressure drop, weight of sediment and appearance, are averaged arithmetically to obtain the overall Accelerated Filter Plugging Test demerit value for the oil. Results obtained in this test are reproducible to 1-0.3.

The oil employed in the Accelerated Filter Plugging Tests was a heating oil having properties substantially the same as those of the oil described in Example 1. Tests were also made on samples of this oil containing the polymeric dispersant additives described in Examples 1 and 2 and upon samples contaning both the polymeric dispersant additives and dicoco dimethyl ammonichloride. Table III.

The results of these tests are set forth in TABLE III.EFFECT OF DICOCO DIMETHYL AMMONIUM CHLORIDE ON FUEL STABILITY 1 Polymeric dispersant A was a copolymer of 1 mol. of vinyl acetate, 0.25 mols. of lsooctyl chloropropyleneoxy maleate, and 0.75 mols. of mixed Ola-Q13 alkyl fumarate, 50% concentration in benzene.

2 Polymeric dispersant B was a mixture of 8 parts of a C tertiary alkyl primary amine and 1 part of a copolymer prepared from 8 parts of Lorol methacrylate and 2 parts of beta diethylaminoethyl methacrylate.

[From the foregoing table it is evident that the addition of dicoco dimethyl ammonium chloride to pertoleum distillate fuels and products containing polymeric dispersant additives does not adversely eiiect the stability of such fuels or interfere with the stabilizing action of the polymeric additives. At the concentrations in which they are used, the ammonium chloride compounds reduce the ability of the dispersants to suspend water but do not reduce their ability to suspend insoluble re action products formed in the oil. The data in Table III suggest that in some instances it may be preferred to limit the amount of dicoco dimethyl ammonium chloride added to oils containing polymeric dispersant stabilizing additives to about 0.001 wt. percent or less. The

demerit rating of the sample containing 0.01% of Dis persant A and 0.0005% of the chloride was slightly better than that of the sample containing the same amount of the polymeric dispersant and 0.001% of the chloride. The data are consistent within the reproducibility of the test.

1 3 EXAMPLE 4 Further tests similar to those described in the preceding examples were carried out in order to demonstrate the effect of the additives of the invention upon fuels and similar hydrocarbon oils employed in contact with aqueous pipeline corrosion inhibitor. Samples of a base heating oil containing 0.01 wt. percent of a commercial polymeric dispersant additive and various amounts of dicoco dimethyl ammonium chloride were extracted with 0.1 vol. percent of a commercial pipeline inhibitor solution. These extracted samples were then subjected to Waring Blendor Haze Tests. The results of these tests are shown in Table IV.

TABLE IV.EFFECT OF EXTRACTION WITH PIPELINE INHIBITOR UPON TETRAALKYL AMMONIUM CHLORIDE HAZE PREVENTIVE Percent Light Transmission Aiter 6 Hrs.

Fuel Following Extraction With Pipeline Inhibitor Solution 1 Base fuel 0.01% Polymeric Dispersant B 51 Base fuel 0.01% Polymeric Dispersant B 2 0.00076% Dicoco Dimethyl Ammonium Chloride 94 Base fuel 0.01% Polymeric Dispersant B 2 0.00068% Dicoco Dimethyl Ammonium Chloride 90 Base fuel 0.01% Polymeric Dispersant B 2 0.00060% Dicoco Dimethyl Ammonium Chi ide 84 or Base fuel 0.01% Polymeric Dispersant B 2 0.0005% Dicoco Dimethyl Ammonium Chloride 96 l The inhibitor was an aqueous solution used commercially for preventing pipeline corrosion and consists of 720 gms. of N aNO and 8.6 gms. of N aOH in 2000 ml. of distilled water.

2 Polymeric Dispersant B was a mixture of 8 parts of a C1 tertiary alkyl primary amine and 1 part of a copolymer prepared from 8 parts of Lorol methacrylate and 2 parts of beta diethylaminoethyl methacrylate.

varying the concentration of the dicoco dimethyl am-v monium chloride and indicate that the additive is particularly effective at concentrations of about 0.0005 wt. percent.

Example 5 It has been found that the dialkyl dimethyl ammonium salts employed in accordance with the invention are eftective for preventing the formation of persistent haze in hydrocarbon oils only in cases where the quaternary additives are present in the organic liquid prior to its being contacted with water. The quaternary ammonium salt may be added to the liquid prior or after the addition of other additive agents such as the dispersant polymer, and thus the salt may be incorporated in fuels prior to entering pipelines or storage tanks to prevent stable water emulsions, and the surface active additives added later at the destination. The additive does not resolve haze which is already present in the oil. This is illustrated by a series of tests wherein dicoco dimethyl ammonium chloride was added to separate samples of a heating oil containing a polymeric dispersant additive after the formation of haze in the oil in the Waring Blendor. The results of these tests are summarized in Table V and it can be seen that the addition of the salt after haze formation had no effect whatsoever.

TABLE V.-EFFECT OF ADDITION OF DICOCO DIMETHYL KiBiIE ISNIUM CHLORIDE TO FUELS CONTAINING WATER Waring Blendor Haze Test, Percent Light Transmission After 6 Hrs.

Fuel

Polymeric Dispersant B was a mixture of 8 parts of a C12 tertiary alkyl primary amine and 1 part of a copolymer prepared from 8 parts of Lorol methacrylate and 2 parts of beta diethylaminoethyl methacrylate.

Example 6 In order to further test the effectiveness of dicoco dimethyl ammonium chloride, full-scale tanker tests were carried out by transporting 140,000 barrels of heating oil containing 0.005 wt. percent of a polymeric stabilizing additive in an ocean-going tanker from the Gulf coast to a New Jersey port. The additive employed was a mixture of 8 parts of a C tertiary alkyl primary amine and 1 part of a copolymer prepared from 8 parts of Lorol methacrylate and 2 parts of beta diethylaminoethyl methacrylate. About 80,000 barrels of the oil contained 0.0005 wt. percent of dicoco dimethyl ammonium chloride. This oil was transported in 7 tanks of the ship. The remaining 60,000 barrels of oil was free of haze inhibitor and was transported in 12 tanks of the ship. There was about 4 inches of Water in the bottom of each tank.

Upon completion of the voyage, the oil containing the dicoco dimethyl ammonium chloride and the oil free of the inhibitor were pumped into separate shore tanks of 112,000 barrels capacity. Hourly haze readings (percent haze equals 100% transmission relative to fuel filtered bright) were made during the pumping at (1) the line on the dock, (2) the line on the shore, and (3) the receiving tank. Haze readings on the line at the dock showed initial values of to with and without the ammonium chloride. The haze thereafter leveled off during pumping at from 45 to 50% in the oil which did not contain the additive of the invention; whereas haze in the oil containing the additive leveled off at from 7 to 8%. The other haze readings showed similar advantages for the additive.

After completion of the pumping described above, settling of the haze in the two shore tanks was observed at intervals for several days. The oil containing the dicoco dimethyl ammonium chloride had settled to 10% haze in 20 hours and contained only 1% haze after 62 hours. After 64 hours the oil without the additive had leveled off at 11% haze.

Example 7 A turbo-jet engine fuel boiling between 275 F. and 480 F. contains 0.02 wt. percent of a copolymer of 50 parts of decyl methacrylate, 30 parts of octadecyl styrene and 20 parts of 4-vinyl pyridine as a polymeric dispersant stabilizing additive. The Water tolerance properties of this fuel are improved by the addition of 0.002 wt. percent of didodecyl dimethyl ammonium chloride.

Example 8 A diesel fuel is stablized by the incorporation therein of 0.01 wt. percent of a copolymer of 80 parts of lauryl acrylate and 20 parts of beta methylamino butyl vinyl ether and 0.08 wt. percent of a mixture of tertiary alkyl primary amines derived from C to C polypropylene. To this fuel is added 0.008 wt. percent of dodecyl tetradecyl dimethyl ammonium chloride in order to improve its water tolerance.

Example 9 A typical #2 heating oil containing a pour depressant amount of about 0.06 wt. percent of a copolymer additive prepared by copolymerizing the ethylene and vinyl acetate with a di-tert-butyl peroxide initiator in a henzene solvent at a temperature of 300 F. and pressure of 750 p.s.i.a. to yield a polymer having about 28 wt. percent of vinyl acetate and a molecular weight of between 1500 and 2200 was considerably enhanced in water tolerance characteristics by the addition of about 0.004 wt. percent of a dimethyl dicoco quaternary ammonium chloride.

Example 10 A hydrocarbon lubricating oil obtained from a paraffinic or naphthenic crude or mixtures thereof of from 100 SUS at 100 F. to about 100 SUS at 210 F. and blends thereof with synthetic oil of lubricating viscosity such as polymerized olefins, copolymers of alkylene oxides and alkyl'ene glycols, organic esters such as di-(2-ethylhexyl) sebacate and the like, and containing about 0.1 wt. percent of a detergent and antiwear polymeric additive produced by the copolymerization at about 60 C. with a benzoyl peroxide catalyst of about 71.8 mole percent of vinyl acetate, 3.0 mole percent of maleic anhydride, and 7.4 mole percent of ditallow fumarate and 17.8 mole percent of di-C -oxo fumarate and containing about 0.006 wt. percent of a dimethyl dicoco quaternary ammonium hydroxide, has a significantly reduced tendency to form stable water emulsions when contacted by water.

Example 11 A premium motor gasoline having from 20 to 60% of aromatic hydrocarbons, less than 30% ol'efinic hydrocarbons, more than 20% saturates, a minor amount of an alkyl lead antiknock agent such as tetraethyl lead, and containing about 0.01 wt. percent of the detergent copolymer of Example 10 and about 0.015 wt. percent of a phosphosulfurized detergent polymer prepared by treating a polyisobutylene of about 900 average molecular weight with about 15 wt. percent of P 8 for 8 hours at a temperature of from 180 to 220 C., blowing the product with steam for 4 hours and neutralizing the steam blown product with from 1 to moles per mole of product with ethylene oxide or urea, is inhibited in haze formation by the addition of about 0.008 wt. percent of a dimethyl dicoco quaternary ammonium bromide.

Example 12 A motor gasoline containing from 0.5 to 4.6 cc. of an alkyl lead antiknock agent, preferably tetramethyl lead, and which contains additionally about 0.05 wt. percent of an ashless, oil soluble copolymer prepared by the copolymerization of about 80 mole percent of lauryl methacrylate with about 20 mole percent of 3,5-dimethyl-N- vinyl pyrrolidone and which polymer containing gasoline composition tends to form stable oil-in-water emulsions when contacted with an aqueous phase is effectively upgraded in Water shedding properties by the addition of between about 0.001 and 0.005 wt. percent of a dimethyl dicoco quarternary ammonium hydroxide.

1 5 Example 13 A superior aviation gasoline providing enhanced water tolerance characteristics is prepared by incorporating about 0.009 wt. percent of a dimethyl dicoco quaternary ammonium acetate in an aviation gasoline having an initial ASTM boiling point of about 105 F. and an ASTM end boiling point of about 315 F. and containing about 4 cc./ gal. of tetraethyl lead, 1.0 theory of ethylene dibromide, and 0.008 wt. percent of an ashless oil soluble N-alkylene amino monoalkenyl succinimide prepared by reacting about 1 mole of a polybutene having an average molecular weight of between 1200 and 1600 with about 1 mole of maleic anhydride and reacting the product with about 1 mole of a tetraethylene pentaamine mixture to produce an oil soluble detergent polymer.

Example 14 A perchloroethylene dry cleaning solvent containing about 0.005 wt. percent of a polymeric dispersant of the type described in Example 1 has a reduced tendency to promote water emulsion and haze when contacted with water by the addition of about 0.005 wt. percent of a dimethyl dicoco quaternary ammonium chloride.

Example 15 An aviation turbo fuel of enhanced thermal stability and water tolerance characteristics is prepared by the addition of 0.05 wt. percent of an ashless dispersant copolymer A of Example 1, 0.005 wt. percent of a diamine metal deactivator and 0.006 wt. percent of a dimethyl dialkyl C C quaternary ammonium salt.

The preceding examples illustrate the effect of dicoco dimethyl ammonium chloride and closely related compounds upon the formation of persistent haze and stable emulsions in organic liquids and hydrocarbon oils. The dialkyl dimethyl ammonium chlorides having alkyl groups consisting of at least 50% C -C radicals reduce both haze formation and emulsification, even though Water extracted; whereas other closely related compounds are ineffective to reduce haze, have no effect upon emulsification, or are almost completely extracted from the oil by small amounts of Water. A wide variety of commercial demulsifiers, many of which are believed to be imidazolinium compounds and other quaternary ammonium salts, have no beneficial effect upon haze formation and emulsification in the presence of polymeric dispersant stabilizing additives or actually increase haze formation in such oils. This singular effectiveness of the additives of the invention permits a significant improvement in the properties of petroleum products, simplifies the handling and storage of such products, and increases their marketability.

What is claimed is:

1. A water immiscible organic liquid boiling in the range betwen about F. and about 900 F. having incorporated therein about 0.001 wt. percent to about 1 wt. percent of an ashless oil-soluble polymeric additive, selected from the group consisting of (a) a copolymer of a vinyl substituted heterocyclic nitrogen base compound and an aliphatic ester of an acrylic acid; (b) a copolymer of maleic anhydride, a vinyl ester of a fatty acid and an aliphatic ester of a butenedioic acid; (c) a copolymer of ethylene and a vinyl ester of a C C fatty acid; (d) the reaction product of a phosphosulfurizing agent with a C -C polymonoolefin; and (e) .a C -C alkenyl succinic acid anhydride and its neutralized products and derivatives, and about 0.00025 wt. percent to about 0.01 Wt. percent of a dialkyl dimethyl ammonium salt in which at least 50% of the alkyl groups are C C radicals.

2. A liquid as defined by claim 1 wherein said organic liquid is a hydrocarbon oil boiling in the range between about 75 F. and 750 F.

3. A liquid as defined by claim 1 wherein said polymeric additive is a pour point depressant, oil soluble copolymer of ethylene and from 1 to about 40 weight per- References Cited by the Examiner UNITED STATES PATENTS 5/1951 Eberz 44-71 5/1956 Catlin et al. 4471 18 2,805,925 10/1957 Biswell 4462 2,861,874 11/1958 OKelly et a1. 4472 2,978,302 4/1961 Siegel et al 4462 3,008,813 11/1961 Siegel 4472 DANIEL E. WYMAN, Primary Examiner.

ALPHONSO D. SULLIVAN, Examiner.

10 Y. M. HARRIS, Assistant Examiner. 

1. A WATER IMMISCIBLE ORGANIC LIQUID BOILING IN THE RANGE BETWEEN ABOUT 75*F. AND ABOUT 900*F. HAVING INCORPORATED THEREIN ABOUT 0.001 WT. PERCENT TO ABOUT 1 WT. PERCENT OF AN ASHLESS OIL-SOLUBLE POLYMERIC ADDITIVE, SELECTED FROM THE GROUP CONSISTING OF (A) A COPOLYMER OF A VINYL SUBSTITUTED HETEROCYCLIC NITROGEN BASE COMPOUND AND AN ALIPHATIC ESTER OF AN ACRYLIC ACID; (B) A COPOLYMER OF MALEIC ANHYDRIDE, A VINYL ESTER OF A FATTY ACID AND AN ALIPHATIC ESTER OF A BUTENEDIOIC ACID; (C) A COPOLYMER OF ETHYLENE AND A VINYL ESTER OF A C2-C18 FATTY ACID; (D) THE REACTION PRODUCT OF A PHOSPHOSULFURIZING AGENT WITH A C2-C6 POLYMONOOLEFIN; AND (E) A C1-C80 ALKENYL SUCCINIC ACID ANHYDRIDE AND ITS NEUTRALIZED PRODUCTS AND DERIVATIVES, AND ABOUT 0.00025 WT. PERCENT TO ABOUT 0.01 WT. PERCENT OF A DIALKYL DIMETHYL AMMONIUM SALT IN WHICH AT LEAST 50% OF THE ALKYL GROUPS ARE C12-C14 RADICALS. 